Holo Audio - Spring DAC - Level 3 - "Kitsune Tuned Edition" - Impressions & Reviews

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  1. Torq

    Torq MOT: Headphone.com

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    Holo Audio - Spring DAC – Level 3 – “Kitsune Tuned Edition”

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    Initial comments …


    Those of you that just want the highlights and don’t want to read a novel, there’s a TL;DR; summary of my thoughts here.

    Additional posts from @Hands, and possibly others, will follow shorty- starting here.

    Disclaimers …

    The DAC I auditioned is the personal unit of the proprietor of Kitsune HiFi/Holo Audio USA. It is the final “Level 3” tuned version of the basic Spring DAC.

    I am not receiving any consideration or perks for reviewing this unit (i.e. no discounts/no special pricing, no early-shipping or queue-jumping or anything else of that nature etc.).

    I approached Tim for a demo unit as part my on-going DAC-search. Although they were all out with various far-more-prominent reviewers, he was gracious enough to loan me his personal DAC for a long weekend, along with a smattering of cables and other relevant goodies.

    History/Context:

    I’m not going to bore you with a page of largely-unrelatable-nonsense about my audio journey; if you want to know my overall gear preferences it’s all in my profile, and you can use the search function here and/or refer to my (“so far”) on-going “Life after Yggdrasil?” thread for perspective on my DAC-auditioning experiences and preferences.

    My principal point of comparison here is going to be to Schiit’s “Yggdrasil” as this remains my primary DAC, despite more than half a year spent looking for something that I might enjoy listening to more (and that meets some other, non-specifically-audio, criteria). That is largely because it’s something I was able to do back-to-back but, also, due to it being a usefully-common reference for a broad array of potential Spring DAC customers/existing Yggdrasil owners.

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    Any commentary that compares to other DACs, unless otherwise noted, is based on memory and my listening notes from those sessions – some of which are months-old now. As such, that means such comparisons are of limited worth and should generally be regarded as high-level impressions.

    Finally, I will save my technical discussion of the DAC and its implementation for another post, as that is going to be of interest more in the context of a formal “all-up” review. However, I’ll say a few words about the principal (from my perspective) innovation in this unit.

    Claim to Fame: Discrete R2R DAC with “Linear Compensation”

    If you’re read my “Life after Yggdrasil” thread, you’ll have observed that my principal interest has been R2R DACs and/or DACs that do more than just couple a “standard audio” DAC chip (most of which are Delta/Sigma designs) with high-spec clocks, fancy power-supplies and excessively “unique” casework for what are, commonly, relatively silly prices.

    The Spring DAC falls into the broader discrete R2R “resistor ladder” category of DACs. Discrete resistor-ladder R2R implementations use individual resistors (or groups of resistors), combined with high-speed switches, to implement the different output levels for each bit-value of a given sample. Leaving aside, for a moment, the realities and limits imposed by thermal and quantum noise in components, a 16-bit DAC needs differentials of 1:65536 (2^16) in the resistances in the “ladder” and a 24-bit DAC requires a ratio of 1:16,777,216 (2^24).

    I’ll talk about this in more detail in the “technical” follow-up, but for now all you need to know is that such implementations are at the mercy of both a) the tolerances of the resistors in the “ladder”, as well as other impedances etc. from the switches and traces that are also part of the circuit etc. and b) these tolerances/resistor values can change with the operating temperature of a unit.

    TotalDAC attempts to get the best accuracy by using naked, trimmed, high-tolerance resistors (currently I believe they’re using resistors toleranced to 0.01%). Metrum uses multiple ladders to span a smaller range of required values (e.g. 2 x 12-bit modules per channel), with additional processing/electronics to combine these values to yield a 24-bit result.

    The Spring DAC uses two separate sets of R2R ladders, one to derive the primary output level and the second to linearly compensate for errors/drift in the primary level. A FPGA provides the necessary platform for the logic and control necessary to make this scheme work.

    Beyond the linear compensation, which is the headline, and (as far as I know) unique, feature for this unit, the Spring DAC also has switchable oversampling/non-oversampling operation and separate decoding path for DSD.

    What is the “Level 3 – Kitsune Tuned Edition” of the Holo Audio Spring DAC?

    This DAC is offered in three versions, and the changes over the standard “Level 1” version of the Spring DAC are unique to Kitsune HiFi (hence the “Kitsune Tuned Edition”) and are installed at the factory at the time the unit is built.

    The changes are as follows:
    • 99.99% silver, custom (hand-wound), 100 VAC O-type transformer
    • All copper wiring is replaced with 1.5mm OCC silver
    • Input film capacitor is replaced with a Mundorf silver/oil capacitor
    • PCB plugs/connectors are removed and direct-wire connections are used
    • Standard IEC inlet replaced with Oyaide pure silver/rhodium plated connector
    • Standard fuse replaced with Audio Horizon Platinum Reference fuse
    • Upgrade to Jensen capacitors
    I cannot speak to any audible differences that may be attributable to these changes, since I have not heard the “Level 1” or “Level 2” versions of the Spring DAC.

    One neat thing I saw on the DAC I auditioned, was an image of the internals of the "Level 3" version applied to the outer casing:

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    Sources and Interfaces:

    I tested with several different sources. My normal setup runs either a Focusrite RedNet 3 or an Auralic Aries (w/ femto clocks and LPS) via AES/EBU XLR into Yggdrasil fed from Roon. I also tested with the USB output from the Aries, a Sonore microRendu and the I2S input via a Singxer SU-1 DDC.

    I did some experimentation with a JCAT USB Isolator (based on the Intona opto-isolators) for the USB feeds as well.

    The vast majority of my testing was done with Red Book audio, with some high-resolution PCM material and maybe a dozen or so “proper” DSD-format albums.

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    Amps, Headphones and Speakers:

    I listened through both my loaded/upgraded Woo Audio WA-5LE Mk2 and Schiit Ragnarok, via JPS Labs “Abyss”, Focal “Utopia”, Audeze “LCD-4” and Sennheiser “HD800S”. Balanced connections were used throughout (the WA5-LE is a single-ended design but has “convenience” balanced inputs/outputs).

    The speaker configuration was a Linn Akurate Kontrol/1 into Akurate 4200 bi-amping Linn Akudorik speakers and a JL Audio Dominion D-108 sub.

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    Level Matching:

    The XLR outputs of the Spring DAC run at 5Vpp RMS compared to Yggdrasil’s 4Vpp RMS. This was immediately noticeable during simple back-to-back listening and you’ll want to match levels to avoid the typical “louder is perceived as better” perception.

    For my testing, I matched levels to within 0.1 dB using a special box I built for performing comparisons and facilitating solo blind-testing. I’ve talked about that a little before if you’re interested.

    Listening:

    I spent my first day, day and a half, prior to getting into any “formal” listening, experimenting with different settings on the Spring DAC, letting it warm up, and just generally relaxing with some music through it. It didn’t take very long to come to the conclusion that I liked the Spring DAC best with PCM sources in “NOS” mode (Non-Over-Sampling).

    That’s a point you should note.

    Almost ALL my serious listening was done playing PCM material with the DAC in NOS mode!

    Outside of DSD-listening, which I’ll come back to, NOS replay is the only mode I would personally use this DAC in. It’s good in over-sampling mode, but other DACs simply do that better/more enjoyably for me, and even driving it with HQ Player I found no combination of settings that I enjoyed as much as I did the Spring’s native NOS replay mode.

    But in NOS mode, well, this is one of the most enjoyable DACs I’ve ever had the pleasure to listen to.

    It’s worth noting, here, that oversampling on this unit is handled by an AK4137 sample-rate-converter (SRC). This is a good quality SRC, but is no match for implementations like that in Yggdrasil that use custom software, DSP processing and Mike Moffat’s “megacomboburrito” time and phase optimized filter.

    Bear in mind that when NOS mode is selected the AK4137 is completely out of the audio path.

    Thus, unless stated otherwise, all comparisons are using NOS mode:

    Detail/Resolution:

    I found the Spring DAC to slightly out-resolve Yggdrasil. This was more noticeable using RCA outputs, but is still apparent using the balanced outputs. Unlike the Vega, which has a tendency to exaggerate detail (which superficially is easy to misinterpret as better actual resolution), I did not get that sense from the Holo Audio unit.

    Another thing I consider when I consider resolution is whether I’m really just hearing brightness, but that isn’t the case here. I hear micro-detail and texturing with the Spring DAC that is modestly better delineated than Yggdrasil’s delivery. I tend to hear this most commonly with brushwork over cymbals, and sometimes drum-skins.

    With Yggdrasil I’m used to having the sense of every individual wire on the brush being more or less discernible as they impact/traverse the surface of the cymbal or drum. On the Spring DAC this was augmented by a perception that I was also hearing wires skipping up and breaking contact with the instrument and then remaking contact.

    Now, if you put the Spring DAC into oversampling mode that perception goes away and I find Yggdrasil moves to the front-runner position on resolution/detail. In fact, I would say that, the advantage Yggdrasil exhibits against the Spring in OS mode is bigger than the Spring has over the Yggdrasil with the Spring in NOS mode.

    But, nevertheless, in NOS mode the Spring was just out-resolving Yggdrasil.

    Attack, Decay, Transients & Dynamics:

    Backgrounds are unearthly quiet with both units. Notes emerge from an inky-black void, and disappear into nothingness with equal aplomb.

    The leading edge of notes seem a tad cleaner with the Spring. I’ll emphasize a “tad” there (and for you non-English types, a “tad” is best thought of as “really not much at all”).

    The plucking/picking, of strings in “Along this Road: Kono Michi (Yv)” (Ottmar Leibert, “One Guitar”) provides an excellent demonstration of the impressive attack, and instant emergence from the, entirely-black background, of individual notes, that the Spring DAC is capable of.

    Percussion is similarly portrayed, with attack and transient response of the impact of a stick on a snare seeming more visceral than via Yggdrasil. This tends to emphasize one’s perception of the raw dynamics of the unit as well.

    Decay was natural, and while it took listening to pieces with predominantly electronic instruments (that can exhibit literally instant decay), the end of notes in that case also were slightly cleaner than with Yggdrasil.

    Dynamics are excellent and, with speakers, highly visceral. Shock-you-out-of-your chair level stuff with big dynamic bursts out of silent passages. The super-fast attack of the Spring DAC does, as I mentioned, emphasize that a tiny bit, and I find that a bit addictive.

    Once again, and this will be a bit of a theme here, turn on oversampling in the Spring DAC and the Yggdrasil switches places and delivers the better performance. As it happens I did not find a single instance in which I liked the Spring DAC better than Yggdrasil if the Spring DAC was using oversampling … which is a long-winded, and repetitive, way of saying “you buy the Spring DAC for its performance as a NOS DAC first – anything else is a bonus/convenience”).

    Soundstage/Imaging:

    While resolution was the first thing to strike me about Holo Audio’s product, the second, was the soundstage it projected and how it imaged.

    Even with headphones, the soundstage projected from the Spring is noticeably wider and deeper (with Abyss and HD800S, since depth is less apparent with any of these DACs on the LCD-4 and, to a certain extent, the Utopia) than I’m used to with Yggdrasil. The image within is very stable. It’s not at all hard to pick out individual instruments spatially.

    As with Yggdrasil, the Spring DAC imaged well enough that I can easily hear where, spatially (left to right) where a note is struck on a piano and it’s not at all hard to follow scales and progressions as they run up and down the keyboard. Chords are clearly left-biased and melody right.

    Now, I never leave my soundstage/imaging comparisons to just headphones as they’re simply not as capable of exploring that the way a properly set up speaker system is …

    And here it becomes apparent to me that Yggdrasil is projecting a more realistic soundstage. I felt the Spring DAC was presenting things as being deeper and wider than they actually are. I’ve sat at the keyboard of my piano enough to know how wide it is supposed to sound and there, and in recordings of that (whether from my playing or visiting concert-level pianists), and Yggdrasil just completely nails that. In contrast the Spring throws the image wider than I find entirely natural or realistic – which is fun, and maybe even desirable with some headphones, but I would go for Yggdrasil’s rendering here every time.

    Yggdrasil also manages to convey height more convincingly. This is really hard to realize properly even for a well setup system with appropriate source material and a cooperative room. There is a sense of height to the Spring’s portrayal, but it’s behind Yggdrasil with the Spring’s image being both much less convincing and less stable.

    Both of these units will let you hear who moved their chair, which violin flubbed a note, or even where on a Timpani the mallet actually (from spatial cues, if the recording has them, as well as the change in tone), just they’ll be spread out more on the Spring.

    In oversampling mode I found Spring’s soundstage to compress a fair bit. This reins in the exaggerated (for me) width and height (winds up narrower and shallower than the Schiit DAC, but it also hampers the precision and stability of the projected image. That’s another way of “just run this thing in NOS mode”!

    Tonality & Timbre:

    I hear Yggdrasil as being essentially neutral and realistic. I don’t hear coloration here. Whether this is down to me being so familiar with it, or whether it’s just really that neutral is hard to say. Though as one of my principal references, the piano, sounds exactly how I expect it to via Yggdrasil, I’m inclined to believe it’s simply uncolored.

    While I wouldn’t go as far as saying that I hear any specific coloration in the rendering from the Spring DAC, it has a definite “sweetness” to its sound. I’ve heard this with a lot of NOS DACs, and while I’ve described it differently (I used the term “glow” in regards to the Metrum Pavane, for example), I find that “sweetness” with the Spring to be quite delightful. It’s not quite a euphonic thing, but it’s very engaging and enjoyable, seductive even. It doesn’t intrude on balance or detail, it doesn’t even feel like it’s straying from neutral, but still it sounds, well, “sweet”.

    I don’t know what causes this; BUT, whatever it is, I find I like it a great deal.

    It’s worth noting that using OS mode on the Spring essentially kills this effect for me.

    That said, Yggdrasil may just be tonally purer, and still provides the best overall rendition of piano that I’ve heard in the digital world. In fact, Yggdrasil is, I think, the best reproduction of recorded piano I’ve ever heard period, as with sustained notes I can usually discern pitch variation even from the best of the turntable systems I’ve had the pleasure to run into.

    Getting back on point, though …

    Instruments sound natural and are just as easy to identify with the Spring DAC as they are with Yggdrasil. Even when there’s a lot going on, you’re not going to confuse violins with viola, or a glockenspiel with a xylophone (might be a stretch that you’d confused those last two anyway, but I’ve certainly seen that happen).

    Discordant piano or brass keeps its edge and bite on Yggdrasil without feeling strident or uncomfortable, but in NOS mode on the Spring sometimes felt a little too edgy. Not much. Not problematically so; but still a bit raw. In OS mode, the stridency went away but so did a little of the bite. Not a big deal, but Yggdrasil handles this better in either case.

    So … this is more of a signature preference and mood, music (and maybe my blood-alcohol level) have as much to do with which signature I prefer at any given time. Both are wonderful, and while I give the nod to Yggdrasil on tonal accuracy overall, that’s not to say I necessarily prefer it.

    Balance:

    Presentation is very even handed, even with the apparent “sweetness” of the Spring DAC and there is no apparent emphasis or recession anywhere I could hear.

    Bass is solid and properly extended with good slam, articulation and weight and provides a firm foundation for the rest of the music. Yggdrasil may have a wee bit more presence in the lower registers, but I’m by no means sure that’s not expectation bias, since I didn’t hear it that way consistently.

    One might say the Spring DAC is a bit moister than Yggdrasil, but I wouldn’t describe it as wet.

    Again, sweetness excepted, I’d put the mid-range performance at essentially the same level, excepting when there is a LOT going on (busy, full-blown orchestral pieces), in which case there seems to be an occasional hint of … I can’t find a suitable word … “something” the puts a very feint mist over things in the lower mid-range.

    I suspect that is down to some IMD product or other NOS artifact, as it is one of those things that goes away in OS mode. However, it’s a very small effect when it is present, and if you’re not listening in “audition” mode, I’d be very surprised if it was apparent at all.

    One thing that was more apparent, but that is also fixed by running in OS mode, is a very slight tendency towards sibilance with some recordings. The Spring DAC is not adding/causing it (I don’t think, or see how, really), but it’s more apparent with the Spring than it is with Schiit’s unit. Turn on OS mode and this goes a bit too far the other way.

    Interfaces and Inputs:

    For those that worry about such things I found that there were small but audible differences, between the Spring DAC’s various inputs. I would rank these as follows:

    I2S > AES >= COAX >= TOSLINK > USB​

    The I2S input was fed via a Singxer SU-1. I did not find any benefit in putting the JCAT Isolator ahead of the SU-1.

    The AES input was driven by my Aries and RedNet 3. I could not reliably tell these apart via the Spring DAC, even with a fully-synchronized blind test. The Aries is less hassle, the RedNet 3 is cheaper, both have their own quirks, and I’ll talk more specifically about those in a dedicated thread on AOIP/NAI devices.

    The USB input on the Spring DAC did benefit from the JCAT Isolator, even when fed out of the microRendu, which surprised me. Coming off the Aries’ USB output I found no difference with, or without, the JCAT Isolator in the chain.

    Note: If you want to run native-DSD (i.e. not via DoP), or run multi-rate DSD, then you’ll need to utilize either the I2S or USB interfaces. And in that case I’d go with the I2S interface, even though it requires something like the SU-1 (at $400).

    DSD Playback:

    I’m on record as not having much interest in DSD. The catalog is tiny. The files are huge. I’ve never heard a convincing demonstration of its alleged sonic superiority. Any time DSD has come out ahead in my listening it has been down to the masters (the most common case) or some artifact of the way the DAC in question processes, e.g. the PS Audio Direct Stream units, which convert everything to DSD before it reaches their D to A stage.

    The Spring DAC renders simply the best/most enjoyable DSD playback I’ve heard so far.

    If you are a DSD proponent, have a lot (relatively speaking) of DSD content, or want a DAC that has great performance with DSD as a format/content-hedge, then you should spend the time and energy to listen to this thing.

    And it’s worth nothing that, via I2S or USB, Holo Audio’s offering doesn’t have the dropout issues that I ran into, and was unable to resolve, with Chord’s DACs (more of an issue with macOS, but they still occur under Windows).

    Caveats about audio-memory and note-based comparisons apply here (albeit that is very recent memory, and lots of time, with the Vega and Direct Stream Junior), but this is the first time any DAC’s performance with DSD has prompted me to go buy a bunch of DSD content due to how much I was enjoying it.

    And I still wouldn’t put DSD ahead of PCM in terms of actual/general realized quality, but for the first time I’ve found a DAC that plays DSD content at a level where I wouldn’t hesitate to buy either DSD-only/native content, or to more readily explore DSD versions of content that exists in both DSD and PCM formats (and, in fact, I did just that, roughly tripling the size of my DSD collection so far).

    Other Thoughts:

    Going beyond how the thing sounds and works …

    Build/Fit & Finish:

    Build is very solid and the Spring DAC is a lot weightier than I would have figured. The chassis is nicely finished, the copper components look quite classy against the black. The large display is dimmable and defeatable.

    It looks and feels the part, without devolving into making one wonder if the casework consumed the bulk of the parts budget.

    Spring DAC “Levels”:

    Kitsune HiFi/Holo Audio offer the Spring DAC in three variations. I was listening to the “top of the line” model, the “Kitsune Tuned” Level 3. This adds several tweaks, mentioned earlier in these comments.

    I have no idea how this unit compares to the Level 1 and 2 units, as I’ve not heard them. This would be the next most interesting thing I would like to explore, since for many if they cannot tell the difference, then there’s a $700 price difference between the Level 1 and the Level 3.

    However, for me personally that price differential isn’t significant enough for me to expend the time to actually look at the less expensive models and, I’d simply opt for the Level 3.

    In Summary:

    The bottom line here is that I enjoyed the Spring DAC enough to want one in my system. That means I’m buying one. It’s the most musical and enjoyable NOS DAC that I’ve heard so far, and doesn’t give up anything on the technical side.

    While I would need to run it back to back to be 100% sure, right now I have to say that, right now, I’d personally rather have the Spring DAC than the Metrum Pavane (which, up to this point, had been my favorite NOS R2R DAC). That it is half the price and/or that I could have both the Holo Audio unit and an Yggdrasil for the same money, makes that a relatively easy decision for me. Your mileage may vary!

    With the same caveat, it easily bests my interest in the DAVE, Direct Stream Junior, TotalDAC and pretty much every other DAC I’ve auditioned this year.

    I would not sell my Yggdrasil to get the Spring DAC. But I wouldn’t do the opposite either.

    If I didn’t have an Yggdrasil already it would be a very hard decision as to which way I would go. There is no question that Holo Audio are offering are more versatile unit with its ability to operate in both NOS and OS modes, as well as delivering first-rate DSD replay. Its oversampled replay doesn’t quite reach the level that Yggdrasil does for me, but then that’s all Yggdrasil does.

    For me, the perfect solution right now is to keep Yggdrasil and add a Spring DAC. This gives me the best of all-worlds.

    If I didn’t have Yggdrasil already, and was only in the market for one DAC then the Spring DAC would be a worthy alternative and is something I consider to be properly competitive with Yggdrasil.

    And if I wanted a fully competitive DAC with DSD support, then this would be an easy choice.

    Very impressive, entirely enjoyable and well worth auditioning.

    And since much of what might drive me one way or the other, if pushed to only have a single DAC, is based on signature preference, you’ll probably need to audition these two units to make an appropriate choice.
     
    Last edited: Nov 7, 2016
  2. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Intro - Oversampling vs Non-Oversampling Thoughts (Subjective)

    First, let me give my usual spiel on the key ways I think oversampling and non-oversampling DACs differ subjectively. If you've read my thoughts on this topic before, skip down to impressions.

    - Key difference is a sense of 3D body between non-oversampling and oversampling. With oversampling, each item in the music, whether that be vocals, guitars, drums, pianos, farts, etc., seem to be a bit compressed on a 2D plane. Layers, width, depth, and all the individual elements residing in the music, with oversampling, tend to be more clearly defined, but at the expense of having 2D planes in which the items all reside. Non-oversampling tends to keep the natural body and 3D nature of everything intact. Vocals sound more tangible and seem like they're coming from a person with a chest cavity rather than being a singing, floating face. That full sense of reverb within an acoustic guitar's body is more present. The downside is that, as mentioned, oversampling is still a bit more clearly defined and focused sounding.

    - Tone, and timbre to an extent. Oversampling is almost always going to sound a bit brighter, or to some, a bit more towards a stereotypical digital sound. Non-oversampling has warmer tone to it. I'd be quick to say it's the high-frequency roll-off on redbook content with non-oversampling that does this, but even music with a high sampling rate on non-oversampling DACs tends to be a bit warmer...arguably more organic sounding. (Non-oversampling with really well done, actually high-res samping rate content is awesome.) That's not to say you can't have fat, warm sounding OS DACs or lean, bright sounding NOS DACs, but I'm generalizing.

    - Speed and micro-dynamics. I get it, maybe music doesn't really contain sharp transients that are commonly used to show filter ringing in DAC measurements. Maybe it's not actually audible. But I know I'm not the only one to think that oversampling tends to smear transients a bit and compress micro-dynamics a tad despite oversampling sounding sharper and more focused overall. Non-oversampling has this natural way of getting me into the groove and swing of music, where as oversampling DACs are less likely to do so.

    - Listening fatigue. I find myself fatigued listening to most oversampling DACs in long listening sessions at high volumes. Non-oversampling stresses me less and leads to longer listening sessions. Non-oversampling was actually wonderful for me to "discover," since I was having issues with listening fatigue that I couldn't pin on amps or headphones. However, I recognize I am in a minority here...a very small minority.

    Long story short, you either prefer oversampling or non-oversampling. I prefer the latter. Most prefer oversampling. My favorite oversampling method thus far is found in the Schiit multibit DACs, or some other slow-roll off filters that sit somewhere in between commonly used oversampling methods and non-oversampling. The only way to find out is to try a good non-oversampling DAC. Some will be converted, the vast majority will not.

    And, again, these are all generalizations. They often hold true when reviewing non-oversampling DACs. Thankfully, a new breed of DACs on the market are looking to shake things up and break free of the usual assumptions...in some ways.

    Holo Audio Spring DAC Impressions (Level 3, minus some later additions like a fancy fuse, fancier internal wiring, and a fancier PSU cap at the door...but close enough)

    Very powerful sounding. Robust low-end, possibly too much on bassy equipment, but relatively tight and detailed. The Yggdrasil might be more taut and pristine sounding based on memory, but, again, this ties in with my general OS vs NOS thoughts. This also leads to a great sense of macro-dynamics on the Spring. I enjoy the bass characteristics, but I imagine some will find it too bassy depending on their rigs. With my modded HD650s or modded Elears from the Jotunheim, it sounds fantastic! With my modded Super 7, I might need to rethink my current tube choices. Maybe. But often the sheer bass authority rustles my jimmies.

    Great sense of resolution. I find the Spring and Pavane to be on a similar playing field here, both of which matched the Yggdrasil to my ears, albeit with that sweetness and hint of softness associated with NOS DACs. Forget the NOS DACs of the past. The Spring and Pavane have set a new bar for NOS DACs with minimal compromises in terms of resolving ability. They really seem to dig deep. Of course, things like cymbals still tend to be best defined and most crisp on a good oversampling DAC. Some things will never change, and that's the nature of the two ideologies.

    Excellent stage width and layering. Not the usual condensed or even claustrophobic NOS stage. Forward, yes, but wide, airy, and layered. This is not what I'd call a laid-back DAC both in dynamics and staging. I think this does well with headphones. It could be too much for speakers. On the other hand, the source I use is rather focused sounding and not like the usual smeared + stretched taffy covered in fuzz sort of sound you get from anything that touches USB. To me, it sounds balanced. With other sources, it could lead to a diffuse, overly-wide stage.

    Tone is very well integrated. While I have yet to hear the Level 3 DACs with fuse upgrades, slight internal wiring upgrades, and a PSU cap upgrade, I would say the Spring is a fairly warm sounding DAC without sounding overly colored. Brighter and less warm than what you'd hear out of, say, a TDA1541A, but less bright than a Gungnir Multibit. However, given higher resolution content (sampling rate, that is), it's more of a neutral-warm. Yes, the treble roll-off with redbook content does have some audibility to it on non-oversampling DACs. Some won't get on with this well.

    Timbre is where I want to nitpick, despite it overall being very good. There's a slight sense of dryness and exaggeration in the upper-mids and lower-treble. While normally I'd file this under a tonal category, it mostly manifests itself in a...how do I put it...very subtly over-textured feeling with any music that is already a bit rough around the edges. Don't get me wrong, as the DAC is overall rather smooth and sweet sounding compared to most DACs. On the other hand, it's possible that, given the excellent specs of the DAC, it's digging out things like additional guitar distortion in rock or metal that other DACs gloss over. I honestly do not mind it and did not notice until others picked it up, so it's incredibly subtle and minor in my mind. (The Valhalla 2, for example, did something similar but to a much more noticeable degree. The fact this flew under my radar, compared to the Valhalla 2, should clarify how minor this is.)

    However, regarding timbre, much of this is erased if the DAC is left on all the time. There's a reason the DAC has a standby mode that keeps everything nice and toasty inside while drawing less power. Still, compared to the latest gen Metrums, the Pavane and Menuet are a bit sweeter and smoother sounding. Speaking of Metrum...

    Spring vs. Metrum Menuet

    My Spring vs. Pavane listening conditions were less than ideal for a variety of reasons (unfamiliar amp w/ even more unfamiliar tubes + no way to quickly A/B + limited time + a couple beers dulling my senses). So, I got a loaner Menuet to compare, and I figure they're closer in price anyway for most.

    The Menuet is less full in the bass and has less macro-dynamics overall compared to the Spring. However, micro-dynamics and a sense of groove are excellent on the Menuet. It might edge out the Spring here, but I found it back-and-forth in my listening tests.

    The Menuet has a slightly more laid-back stage and might have a hair less width. However, depth is quite good, and it sounds like it has good ambiance. I think the Spring captures elements like reverb from the recording just a bit better.

    The Menuet is the smoother sounding DAC. It seemed to pull out the same low-level details for the most part, but with a sweeter, softer characteristic. This isn't the vaseline-smeared sort of smoothness from the first generation Metrum DACs, and it's much more refined sounding than the Musette in almost every way imaginable. The downside to this, while very pleasant, romantic, euphonic, etc., was that it did dull the sense of some details. A 12-string guitar, for example, sounded more lively, brighter, and like a 12-string guitar on the Spring. It was harder to tell on the Menuet.

    On the other other hand, there were times the Menuet seemed to shine a bit more with cymbals sounding sharper and more distinct. This was a tough battle and, again, went back and forth depending on the music. The Menuet occasionally inched ahead with the last two octaves sounding a hair more present, faster, and cleaner compared to the Spring. Sometimes.

    Tonally, there was something about the Spring that sounded more cohesive than the Menuet. TThe Spring sounded well put together. Something about the Menuet seemed missing in comparison, as if the tonal balance wasn't stitched together quite as well. It's as if the upper-bass through lower-mids and last octave on the Menuet weren't in perfect harmony, whereas the Spring didn't have any issues. Very, very subtle. (I recall saying the original Metrums had a sort of earthy quality to them, and I think that's carried over here a bit.)

    By now, you might have determined the Spring and Menuet are much more similar than not. More different than better or worse, and even then, tossing in a Yggdrasil would turn into a game of "one of these things is not like the other."

    The Menuet seemed to suffer the most with SE outputs. The Spring sounded a bit less 3D, articulate, and lively with its SE outputs, but the Menuet really didn't come alive until I ran it balanced. In other words, when comparing Spring balanced out to Menuet SE out, I felt the Spring was comfortably ahead in most regards. Running Spring in SE out vs. the Menuet in balanced out left me feeling more that they were on the same level but had different enough characteristics for varying tastes. I personally got on a bit better with the Spring, as it's a bit more lively, a little less euphonic (despite fuller bass), a bit more powerful, and a bit more resolving in some cases. But the Metrums definitely have this near-indescribable charm to them that I find hard not to love. Tough call.

    (Side notes: At the CO meet, most of the guys felt the Pavane did a better job picking out individual elements in the stage, especially when height was concerned. i.e. They felt the Pavane had more height to it compared to the Spring. They also agreed it sounded smoother than the Spring. I personally found it difficult to determine differences in terms of height and picking out individual items once they let the beer pass through me, but, hey, I won't doubt that they heard what they heard. With a couple beers in me, just enough to dull my senses, I was about to rip my hair out trying to find differences between the Pavane and Spring. The Gungnir Multibit sounded noticeable different in comparison. Overall, Pavane, Spring, and Menuet are often on the same playing field.)

    Wrap-Up

    The Spring is an excellent non-oversampling DAC. Don't buy it because it can oversample or do DSD. I don't get the appeal with DSD, and the oversampling mode on the Spring is generic at best. If you want an oversampled multibit DAC, go with Schiit. If you want DSD, I don't know what to tell you. I guess it doesn't hurt to have those features included in this case, since it's not like they compromises the true reason to buy the Spring. If you want a non-oversampled, PCM DAC, good news! The Spring and upper-tier Metrum DACs of the new generation are starting to blur that line between OS and NOS, meaning less compromises and trade offs with the NOS benefits. (Note the lower level Spring DACs should be a great value for the money.)


    Modest measurements of the Spring here, and Menuet here.
     
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  3. Torq

    Torq MOT: Headphone.com

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    TL;DR; - Holo Audio – Spring DAC – Level 3 “Kitsune Tuned Edition”

    Front.jpg


    Initial thoughts/findings:
    • The Spring DAC is, for me, at its best with PCM content in NOS mode.
    • XLR outputs runs at 5Vpp, so if comparing to Yggdrasil (4Vpp), you’ll want to level match carefully when auditioning.
    • Build and fit/finish are very nice, solid and heavy.
    • First R2R DAC with Linear Compensation (subject for a longer commentary).
    Comparisons are ALL with Yggdrasil, unless otherwise stated. And non-Yggdrasil comparisons are based on audio-memory and extensive listening notes and, while I believe they are accurate, should be taken more as impressions than absolutely definitive statements.

    DACs.jpg

    • Soundstage and Imaging are impressive and pronounced.
    I think the overall soundstage it projects is a little wider and deeper than is actually realistic, but that’s not necessarily a bad thing with headphones.

    In a speaker setup it was a bit too wide compared with Yggdrasil, and didn’t project height as well as Schiit’s unit.​
    • Out-resolves Yggdrasil, with better attack and faster transient response in NOS mode.
    The difference isn’t huge, but it is immediately noticeable, particularly with plucked-strings and some percussions work. In NOS mode there is more detail, faster attack and better transient response than the oversampled Schiit DAC renders.

    In oversampling mode, Yggdrasil does pull ahead of OS mode on the Spring here.​
    • Excellent tonality and balance; gives a little/takes a little depending on whether you’re in OS or NOS mode.
    Not wet, but not dry, a little immediately obvious (and highly seductive) “sweetness” to the sound, yet it doesn’t come across as colored somehow.

    I find Yggdrasil quite neutral, possibly as it’s the DAC I use the most right now.

    Vocals are projected and rendered beautifully, instruments are entirely believable, everything is cohesive and it is very easy to simply get lost in the music.​
    • The best NOS DAC I‘ve heard so far.
    Doing another round with the Metrum Pavane might sway me there, but from memory and my notes I prefer listening to the Spring DAC to the Metrum unit.

    Pavane had an effect I described as “glow” to its presentation, which I’d describe as “sweetness” with the Spring DAC.​
    • DSD Playback
    This is simply the best DSD playback I’ve so far experienced.

    While, to date, DSD has not been my thing (I’ll elaborate in a follow-up post), the Spring DAC gave an impressive showing here and resulted in my more than doubling the size of my DSD library.​
    • You buy this DAC to run in NOS mode!
    While the Spring DAC is an enjoyable listen in all modes, it’s easily at its best in NOS mode. If you switch to oversampling replay then detail/resolution suffers a little, the soundstage gets compressed, presentation loses some of its engaging “sweetness” but softens a little as well.

    If you’re always going to use oversampled replay and don’t need DSD replay then Yggdrasil is, for me, a better choice.

    In other words, if you already know that NOS DACs aren’t your thing, then there are definitely other units you need to include in your auditioning.​
    • Choice of input matters; in decreasing order, I’d rank the inputs as follows:
    I2S > AES >= COAX >= TOSLINK > USB​

    I used a Singxer SU-1 to feed the I2S input and this gave the best overall results. The USB input benefitted from the use of a JCAT Isolator but even then didn’t reach the levels of the AES or I2S interfaces.​

    Summary:

    This is a really impressive unit, that I find entirely musical and engaging and that I want as part of my system. To that end, I am buying myself one.

    While I wouldn’t give up my Yggdrasil for the Holo Audio unit; I wouldn’t do the opposite either.

    The Spring DAC is, I feel, entirely competitive with Yggdrasil, while offering some options that Schiit’s unit doesn’t (choice of NOS and OS mode, as well as first-rate DSD playback).

    Very much worth an audition.
     
    Last edited: Nov 7, 2016
  4. Thenewerguy009

    Thenewerguy009 Friend

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    Torq, do you think you journy for a DAC ended or will you still be on the lookout for more DACs to try?
     
  5. TwoEars

    TwoEars Friend

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    Wow, what a write-up. Bravo! :bow:

    Some additional questions if you have time:

    1) I noticed that you tend to favor acoustic and classical music. I wonder if you listened to any tracks with really deep bass as well? For someone like myself who generally favors electronica and rock this is quite interesting. And it might help shed some light on the bass performance of the spring dac vs the Yggdrasil. If you want a tip one of my favorite test tracks is "massive attack - paradise circus" in flac format, it has some passages with deep bass and is generally a very demanding track.

    2) If you were to rate Yggdrasil, spring (and maybe metrum) on a scale of warm-->neutral how would that turn out?

    3) Similarly if you were to rank the same DAC's on a scale of forgiving-->honest how do you think that would turn out?

    Thanks again for a great review!
     
  6. Torq

    Torq MOT: Headphone.com

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    While I'll always be willing to audition something new and interesting I am, at least in the context of my "Life after Yggdrasil?" search, and certainly for the rest of this year, "done". I'm going to put the Spring DAC in the main system alongside my current Yggdrasil (add likely add another Yggdrasil, but that's another story).

    I would like to put the Spring DAC back-to-back with the Metrum Pavane. That was the prior-best NOS R2R DAC I'd heard (and the only one to make the original shortlist), and it'd be good to do a direct comparison rather than one separated by four full months. I believe @gbeast has a Pavane currently, and he's just down in Portland, so that's probably something that can be arranged once I have my Spring DAC in my hands.

    I'd also like to hear the three "levels" of Spring DAC alongside each other. I know someone locally that has the Level 2, but suspect that's as far as that might go in the near future, but we'll see.

    Sometime next year I'll get the big dCS and MSB stuff in house with Yggdrasil and the Spring DAC, but I'm not in a rush for that. For now I'd rather spend the rather sizable difference in price between this new thing and those units on a major turntable upgrade!
     
  7. Merrick

    Merrick A lidless ear

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    @Torq if you do any A/Bing with @gbeast here in PDX, I'd love to tag along!
     
  8. Torq

    Torq MOT: Headphone.com

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    Thanks!

    I'll have to post my primary audition playlist here in a bit, but it encompasses all genres. I tend to refer to classical and acoustic works more commonly in my write-ups purely because those tend to make it easier (for me) to describe what I'm hearing (lots of electronic music, for example, uses sounds that don't correlate to any actual instrument and that makes referencing it harder). But, I listen to lots of music with prominent bass components.

    A couple of much more modern pieces that I have in my initial playlist are “Partition” (Beyoncé; no, I'm not much of fan) and “Chameleon” (Trentemøller). Both have useful bass elements for comparing extension and articulation (deep enough, and prominent enough, to over-pressure my room even with a very modest sub-woofer). There are quiet a few others. Bass-heads aren't going to be disappointed with the Spring DAC in NOS mode. OS vs. OS you'd want Yggdrasil still. Yggdrasil vs. Spring in it's NOS mode, there's not much in it. Unless you were using Abyss or LCD-4 I doubt you'd be able to tell them apart at all in the bass department. Normally I'd say something about "Moffat Bass" here, but it's less of a factor in this case than any other comparison I've heard.

    In terms of neutrality or, rather, warmth, that's tricky (partly because it's been months since I've heard the Pavane). While I ascribe a sense of "sweetness" to the Spring DAC, I still think it's tonally neutral. I wouldn't conflate "sweetness" here with "warmth". I used the term "glow" with the Pavane, since "warmth" wasn't quite the right way to describe what I heard there either. That's probably not very helpful, but it's really not warmth that I'm hearing, based on my notes and how I interpret that term, in these cases.

    As for "forgiving vs. honest" ... I tend to think of "forgiving" as meaning "covers up harshness/hash/artifacts in the original recording". None of these units really do that. Put the Spring DAC in OS mode and it will to a certain extent, but that's really more in contrast to what you hear in vs. it's NOS mode, or Yggdrasil's superlative OS implementation vs. it glossing over anything in the original material.

    All of them will let you hear the harshness/over-production/grain in many of Prince' tracks (and stuff he did engineering on) around the early-to-mid 80s.

    Sorry if that doesn't really help. I can do some specific, on-request, comparisons once I have my own Spring on hand!
     
  9. Torq

    Torq MOT: Headphone.com

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    The more the merrier as far as I'm concerned.

    Though I'll lobby quite hard to do it at my place (plenty of rooms for overnight/weekend guests) up here as I hate driving "just to get somewhere" (doing it for the fun of it is another matter, but "fun", "driving" and "I-5" are phrases that have yet to coincide for me, even fleetingly). But it's not beyond the realms of possibility that I could be tempted to make the trek down to Portland.
     
  10. Merrick

    Merrick A lidless ear

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    I'll tell you what, not only will I drive up but I'll bring the Orcas with me for a different flavor (if you're interested).
     
  11. Torq

    Torq MOT: Headphone.com

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    As soon as my Spring DAC comes in, then, we'll coordinate something (via PM or separate thread).

    Definitely interested in hearing the Orcas.
     
  12. Merrick

    Merrick A lidless ear

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    [​IMG]

    Okay, I'll stop derailing the thread and ask a serious question: When you say that the soundstage of the Holo sounded too wide, did you find it distracting? Did it take you out of the music in any way?
     
  13. 7Ryder

    7Ryder Friend

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    Yes, "fun" and "I-5" are mutually exclusive. Although when Bend is ultimately the destination (in a couple of weeks), well, I can make an exception.
     
  14. Torq

    Torq MOT: Headphone.com

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    No, not distracting at all.

    If not using speakers and recordings with which I'm familiar with the recording setup and exactly what should be captured/portrayed, all I would have commented on was how expansive the soundstage was. With many headphones I think this actually might be quite desirable (maybe not with the HD800S and Abyss, at least if you have a forward cant on the Abyss).

    I had @Barra over to listen for a bit while I was warming the Spring up (just on headphones) and his first comments were on the soundstage (and then the attack/detail on strings and the "sweetness" to the sound in NOS mode).
     
  15. Merrick

    Merrick A lidless ear

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    Yes, I remember reading that post on HF. I definitely want to hear the two DACs side by side, because I'm having a hard time visualizing the differences in that area.
     
  16. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Eventually I'll add my impressions in that reserved post, but for now...

    I found the Pavane and Spring much more similar than not. A couple beers in, just enough to blur senses, and I was about to go crazy listening for differences. Not that there weren't any, but same playing field. Meanwhile the Gungnir Multibit immediately stood out from the two as different sounding in comparison.

    Both Pavane and Spring have a very wide stage. The former may do heighth better per some other CO guys. I find this wide stage a non-issue in any situation, but my source is also very focused and tight-knit sounding unlike the usual USB stretched taffy smear haze.

    Spring sounds best when left on all the time. That's why it has a standby mode. Alleviates some rough edges. More nuanced. Or I'm full of shit and saying what I want to hear. Could be.

    Some will shit in my cereal for suggesting something like this, but I got some XLR attenuators to lower the hot signal. Used Rothwells, cheap deal. Could clip with some devices without. I use this with a Jensen iso max into my Super 7 and am very happy. SE on Spring sounded noticeably inferior in every way in A/B on Jotun.
     
  17. insidious meme

    insidious meme Ambivalent Kumquat

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  18. gepardcv

    gepardcv Almost "Made"

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    Could you be more specific about the differences?
     
  19. Thenewerguy009

    Thenewerguy009 Friend

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    Yeah, hope you include the Gungnir Multibit in your detailed comparison when you do get around to it.
     
  20. gbeast

    gbeast Mighty Moral Power Ranger

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    Im down I will only bring my Pavane since the rest needs to be the same to eliminate any variables. It'd be better to go up there.
     

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